The human intestinal tract contains trillions of bacteria, collectively called the gut microbiota. The majority of bacteria belong to the Gram-negative phyla Bacteroidetes and Proteobacteria and the Gram-positive phyla Firmicutes and Actinobacteria (1). In humans, the diversity of the gut microbiota and the abundance of species increase rapidly after birth and, after 2 to 4 years, remain relatively stable throughout adult life (2). Nevertheless, shifts in gut microbiota composition may occur, especially after use of antibiotics. Even a short course of antibiotics can result in perturbations that last for several years (3, 4).

Causality of the gut microbiota in different diseases. The gut microbiota may have various levels of causality in diffent diseases. Diseases that have a more complex pathophysiology may respond less to fecal microbiota transplantation. ESBL, extended spectrum beta-lactamase producer; VRE, vancomycin-resistant enterococci; IBD, inflammatory bowel disease; IBS, irritable bowel syndrome; T2D, type 2 diabetes. Modified from Molecular Metabolism with permission of the publisher.

10.1128/9781555819705/fig12-1_thmb.gif

10.1128/9781555819705/fig12-1.gif

Figure 1

Causality of the gut microbiota in different diseases. The gut microbiota may have various levels of causality in diffent diseases. Diseases that have a more complex pathophysiology may respond less to fecal microbiota transplantation. ESBL, extended spectrum beta-lactamase producer; VRE, vancomycin-resistant enterococci; IBD, inflammatory bowel disease; IBS, irritable bowel syndrome; T2D, type 2 diabetes. Modified from Molecular Metabolism with permission of the publisher.

42.RupnikM,, Tambic AndrasevicA,, Trajkovska DokicE,, MatasI,, JovanovicM,, PasicS,, KocuvanA,, JanezicS.2016. Distribution of Clostridium difficile PCR ribotypes and high proportion of 027 and 176 in some hospitals in four South Eastern European countries. Anaerobe42:142–144.[CrossRef][PubMed]